Connecting elements of the present type are chiefly used in microelectronics.
With various commercially available types, the electric contact elements are arranged in chambers of frame-type holders or sockets. These have an elevated rib portion surrounding the chip receptacle. With the aid of a slewably mounted or also snap-on type of frame which is provided with mechanical pressure springs, the chip carrier is pressed with its contact surfaces against the spring ends of the contact elements.
A connecting element is also already known from the European Patent Application No. 0 030 763. Instead of a press-on frame, and for fixing in position the chip carrier, there are provided several strips of spring sheet slewably mounted on respectively one outer side of the pin frame of insulating material.
It is the object of the invention to provide a simple and, from a production technical point of view, cost-effectively producible connecting element for the use with differently thick chip carriers which permits a permanent, elastic connection between the contact surfaces arranged in the marginal range of the chip carrier, and the printed conductors of a printed circuit board.
The electric contact elements can be manufactured in an advantageous manner from simple wire cuttings which, without causing any waste, are cut off a supply reel and simultaneously bent in a simple type of device. Moreover, during the manufacture of the pin frame of insulating material carried out in one single operation, they are injection moulded at the same time. Owing to the freely rising up spring legs and their arrangement touching the chip carrier on its narrow sides, there is effected an automatic equalization of the length, width and thickness tolerances of the chip carrier which are due to the manufacture, i.e., independently of the possible use of different nominal thicknesses. Moreover, there is also effected a lateral compensation of tolerances between the spring legs and the connecting surfaces of the chip carrier. In addition thereto, upon snapping-in of the spring legs, the chip carrier is centered into its semicircular cutouts. When the spring legs of the contact elements are soldered to the connecting surfaces of the chip carrier, the spring legs still remain sufficiently flexible for compensating for the different expansion behaviour of the various materials in all directions in the case of temperature variations. Further advantages are mentioned in the specification.
Examples of embodiment of the invention will now be explained in greater detail with reference to FIGS. 1 to 6 of the accompanying drawings, in which: